U.S. Department of the Interior U.S. Geological Survey

Summary of Surface-Water-Quality Data Collected for the Northern Rockies Intermontane Basins National Water- Quality Assessment Program in the Clark Fork-Pend Oreille and Spokane River Basins, Montana, Idaho, and Washington, Water Years 1999-2001

Open-File Report 02–472

Naa Wae-Qa Aee Pga Summary of Surface-Water-Quality Data Collected for the Northern Rockies Intermontane Basins National Water-Quality Assessment Program in the Clark Fork-Pend Oreille and Spokane River Basins, Montana, Idaho, and Washington, Water Years 1999–2001

By Michael A. Beckwith

Open-File Report 02–472

Boise, Idaho 2003 U.S. DEPARTMENT OF THE INTERIOR Gale A. Norton, Secretary

U.S. GEOLOGICAL SURVEY Charles G. Groat, Director

The use of firm, trade, and brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Government.

Additional information can be obtained from: Copies of this report can be purchased from:

District Chief U.S. Geological Survey U.S. Geological Survey Information Services 230 Collins Road Box 25286 Boise, ID 83702-4520 Federal Center http://idaho.usgs.gov Denver, CO 80225 e-mail: [email protected]

Copies of this report also are available in PDF format, which can be viewed using Adobe Acrobat Reader, at URL: http://idaho.usgs.gov/public/reports.html FOREWORD

The U.S. Geological Survey (USGS) is committed to serve the Nation with accurate and timely scien­ tific information that helps enhance and protect the overall quality of life, and facilitates effective manage­ ment of water, biological, energy, and mineral resources. (http://www.usgs.gov/). Information on the quality of the Nation’s water resources is of critical interest to the USGS because it is so integrally linked to the long-term availability of water that is clean and safe for drinking and recreation and that is suitable for industry, irrigation, and habitat for fish and wildlife. Escalating population growth and increasing demands for the multiple water uses make water availability, now measured in terms of quantity and qual­ ity, even more critical to the long-term sustainability of our communities and ecosystems. The USGS implemented the National Water-Quality Assessment (NAWQA) Program to support national, regional, and local information needs and decisions related to water-quality management and pol- icy. (http://water.usgs.gov/nawqa/). Shaped by and coordinated with ongoing efforts of other Federal, State, and local agencies, the NAWQA Program is designed to answer: What is the condition of our Nation’s streams and ground water? How are the conditions changing over time? How do natural features and human activities affect the quality of streams and ground water, and where are those effects most pro­ nounced? By combining information on water chemistry, physical characteristics, stream habitat, and aquatic life, the NAWQA Program aims to provide science-based insights for current and emerging water issues and priorities. NAWQA results can contribute to informed decisions that result in practical and effective water-resource management and strategies that protect and restore water quality. Since 1991, the NAWQA Program has implemented interdisciplinary assessments in more than 50 of the Nation’s most important river basins and aquifers, referred to as Study Units. (http://water.usgs.gov/nawqa/nawqamap.html). Collectively, these Study Units account for more than 60 percent of the overall water use and population served by public water supply, and are representative of the Nation’s major hydrologic landscapes, priority ecological resources, and agricultural, urban, and natural sources of contamination. Each assessment is guided by a nationally consistent study design and methods of sampling and anal­ ysis. The assessments thereby build local knowledge about water-quality issues and trends in a particular stream or aquifer while providing an understanding of how and why water quality varies regionally and nationally. The consistent, multi-scale approach helps to determine if certain types of water-quality issues are isolated or pervasive, and allows direct comparisons of how human activities and natural processes affect water quality and ecological health in the Nation’s diverse geographic and environmental settings. Comprehensive assessments on pesticides, nutrients, volatile organic compounds, trace metals, and aquatic ecology are developed at the national scale through comparative analysis of the Study-Unit findings. (http://water.usgs.gov/nawqa/natsyn.html). The USGS places high value on the communication and dissemination of credible, timely, and rele­ vant science so that the most recent and available knowledge about water resources can be applied in man­ agement and policy decisions. We hope this NAWQA publication will provide you the needed insights and information to meet your needs, and thereby foster increased awareness and involvement in the protection and restoration of our Nation’s waters. The NAWQA Program recognizes that a national assessment by a single program cannot address all water-resource issues of interest. External coordination at all levels is critical for a fully integrated under- standing of watersheds and for cost-effective management, regulation, and conservation of our Nation’s water resources. The Program, therefore, depends extensively on the advice, cooperation, and information from other Federal, State, interstate, Tribal, and local agencies, non-government organizations, industry, academia, and other stakeholder groups. The assistance and suggestions of all are greatly appreciated.

Robert M. Hirsch Associate Director for Water

Foreword iii CONTENTS

Foreword ...... iii Abstract ...... 1 Introduction ...... 2 Purpose and scope...... 2 Description of study area ...... 2 Environmental history ...... 6 Water-quality sampling and analysis ...... 7 Streamflow and water-quality data ...... 8 Summaries and graphical displays of data ...... 8 Physical and chemical characteristics...... 9 Streamflow ...... 9 Nutrients...... 9 Organic carbon...... 14 Trace elements ...... 14 Comparison with other National Water-Quality Assessment Program studies ...... 17 References cited ...... 17

FIGURES 1. Location of the Northern Rockies Intermontane Basins study area and surface-water-quality sampling sites in Montana, Idaho, and Washington ...... 4 2–11. Graphs showing: 2. Selected streamflow statistics and water-quality sampling dates for the Clark Fork at Turah Bridge near Bonner, Montana (12334550) ...... 23 3. Selected streamflow statistics and water-quality sampling dates for the Bitterroot River near Missoula, Montana (12352500) ...... 24 4. Selected streamflow statistics and water-quality sampling dates for the Clark Fork at St. Regis, Montana (12354500) ...... 25 5. Selected streamflow statistics and water-quality sampling dates for the Flathead River at Perma, Montana (12388700) ...... 26 6. Daily streamflow and water-quality sampling dates for Lightning Creek at Clark Fork, Idaho (12392155) ...... 27 7. Daily streamflow and water-quality sampling dates for the St. Joe River at Red Ives Ranger Station, Idaho (12413875) ...... 28 8. Selected streamflow statistics and water-quality sampling dates for the North Fork Coeur d’Alene River at Enaville, Idaho (12413000) ...... 29 9. Selected streamflow statistics and water-quality sampling dates for the South Fork Coeur d’Alene River near Pinehurst, Idaho (12413470) ...... 30 10. Selected streamflow statistics and water-quality sampling dates for the Spokane River near Post Falls, Idaho (12419000) ...... 31 11. Daily streamflow and water-quality sampling dates for the Spokane River at Seven Mile Bridge near Spokane, Washington (12424500) ...... 32 12–40. Boxplots showing: 12. Distribution of streamflow values for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 33

Contents v 13. Distribution of specific conductance values for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 33 14. Distribution of onsite pH values for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 34 15. Distribution of water temperature values for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 34 16. Distribution of hardness values for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 35 17. Distribution of alkalinity values for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 35 18. Distribution of suspended sediment concentrations for samples collected at surface- water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 36 19. Distribution of dissolved solids concentrations for samples collected at surface-water- quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 36 20. Distribution of total nitrogen concentrations for samples collected at surface-water- quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 37 21. Distribution of total phosphorus concentrations for samples collected at surface-water- quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 37 22. Distribution of dissolved arsenic concentrations for samples collected at surface-water- quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 38 23. Distribution of total recoverable arsenic concentrations for samples collected at surface- water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 38 24. Distribution of dissolved cadmium concentrations for samples collected at surface- water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 39 25. Distribution of total recoverable cadmium concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 39 26. Distribution of dissolved copper concentrations for samples collected at surface-water- quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 40 27. Distribution of total recoverable copper concentrations for samples collected at surface- water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 40 28. Distribution of dissolved lead concentrations for samples collected at surface-water- quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 41 29. Distribution of total recoverable lead concentrations for samples collected at surface- water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 41

vi Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 30. Distribution of total recoverable mercury concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 42 31. Distribution of dissolved zinc concentrations for samples collected at surface-water- quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 43 32. Distribution of total recoverable zinc concentrations for samples collected at surface- water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 43 33. Distribution of dissolved arsenic concentrations for samples collected in surface water in National Water-Quality Assessment study areas in the Western United States affected by historical mining activities ...... 44 34. Distribution of dissolved cadmium concentrations for samples collected in surface water in National Water-Quality Assessment study areas in the Western United States affected by historical mining activities ...... 44 35. Distribution of dissolved copper concentrations for samples collected in surface water in National Water-Quality Assessment study areas in the Western United States affected by historical mining activities ...... 45 36. Distribution of total recoverable copper concentrations for samples collected in surface water in National Water-Quality Assessment study areas in the Western United States affected by historical mining activities ...... 45 37. Distribution of dissolved lead concentrations for samples collected in surface water in National Water-Quality Assessment study areas in the Western United States affected by historical mining activities ...... 46 38. Distribution of total recoverable lead concentrations for samples collected in surface water in National Water-Quality Assessment study areas in the Western United States affected by historical mining activities ...... 46 39. Distribution of dissolved zinc concentrations for samples collected in surface water in National Water-Quality Assessment study areas in the Western United States affected by historical mining activities ...... 47 40. Distribution of total recoverable zinc concentrations for samples collected in surface water in National Water-Quality Assessment study areas in the Western United States affected by historical mining activities ...... 47

TABLES

1. Surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area . . . . . 3 2. Land cover in the Northern Rockies Intermontane Basins study area...... 6 3. Selected physical and chemical characteristics for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001...... 10 4. Nutrient and organic carbon concentrations in samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001, and comparative median concentrations in samples collected for the National Water-Quality Assessment Program and other national monitoring programs ...... 12 5. Selected trace-element data for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001 ...... 15

Contents vii CONVERSION FACTORS AND OTHER ABBREVIATED UNITS

Multiply By To obtain cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s) cubic mile (mi3) 4.168 cubic kilometer (km3) foot (ft) 0.3048 meter (m) inch (in.) 2.54 centimeter (cm) mile (mi) 1.609 kilometer (km) square mile (mi2) 2.590 square kilometer (km2) ton 0.9072 metric ton

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows: °F=(1.8) (°C) + 32

Other abbreviated units: microgram per liter (µg/L) milligram per liter (mg/L)

viii Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 Summary of Surface-Water-Quality Data Collected for the Northern Rockies Intermontane Basins National Water-Quality Assessment Program in the Clark Fork-Pend Oreille and Spokane River Basins, Montana, Idaho, and Washington, Water Years 1999–2001

By Michael A. Beckwith

Abstract ples from most sites were smaller than median concentrations reported for many national pro- Water-quality samples were collected at 10 grams and other NAWQA Program study areas. sites in the Clark Fork-Pend Oreille and Spokane The only exceptions were two sites downstream River Basins in water years 1999 – 2001 as part of from large wastewater-treatment facilities, where the Northern Rockies Intermontane Basins (NROK) median concentrations of total nitrogen exceeded National Water-Quality Assessment (NAWQA) the national median. Maximum concentrations of Program. Sampling sites were located in varied total phosphorus in samples from six sites exceeded environments ranging from small streams and riv­ the 0.1 milligram per liter threshold recommended ers in forested, mountainous headwater areas to for limiting nuisance aquatic growth. Concentra­ large rivers draining diverse landscapes. Two sam­ tions of arsenic, cadmium, copper, lead, mercury, pling sites were located immediately downstream and zinc were largest in samples from sites down- from the large lakes; five sites were located down- stream from historical mining and ore-processing stream from large-scale historical mining and ore- areas in the upper Clark Fork in Montana and the processing areas, which are now the two largest South Fork Coeur d’Alene River in Idaho. Con­ “Superfund” (environmental remediation) sites in centrations of dissolved lead in all 32 samples the Nation. Samples were collected during a wide from the South Fork Coeur d’Alene River exceeded range of streamflow conditions, more frequently the Idaho chronic criterion for the protection of during increasing and high streamflow and less aquatic life at the median hardness level measured frequently during receding and base-flow condi­ during the study. Concentrations of dissolved zinc tions. Sample analyses emphasized major ions, in all samples collected at this site exceeded both nutrients, and selected trace elements. the chronic and acute criteria at all hardness levels Streamflow during the study ranged from measured. more than 130 percent of the long-term average in When all data from all NROK sites were com­ 1999 at some sites to 40 percent of the long-term bined, median concentrations of dissolved arsenic, average in 2001. River and stream water in the dissolved and total recoverable copper, total recov­ study area exhibited small values for specific con­ erable lead, and total recoverable zinc in the NROK ductance, hardness, alkalinity, and dissolved sol- study area appeared to be similar to or slightly ids. Dissolved oxygen concentrations in almost all smaller than median concentrations at sites in samples were near saturation. Median total nitro­ other NAWQA Program study areas in the Western gen and total phosphorus concentrations in sam­ United States affected by historical mining activi-

Abstract 1 ties. Although the NROK median total recoverable subject of this report, the Northern Rockies Intermont­ lead concentration was the smallest among the ane Basins (NROK). three Western study areas compared, concentra­ tions in several NROK samples were an order of Purpose and Scope magnitude larger than the maximum concentra­ tions measured in the Upper Colorado River and This report summarizes water-quality data col­ Great Salt Lake Basins. Dissolved cadmium, dis­ lected at 10 sampling sites in the NROK study area solved lead, and total recoverable zinc concentra­ during water years 1999–2001. Selected data also are tions at NROK sites were more variable than in the compared with regulatory standards and guidelines and other study areas; concentrations ranged over with data from other NAWQA Program studies. almost three orders of magnitude between mini- mum and maximum values; the range of dissolved Description of Study Area zinc concentrations in the NROK study area exceeded three orders of magnitude. The NROK study area includes the Clark Fork- Pend Oreille and Spokane River Basins in northwest- ern Montana, northern Idaho, and northeastern Wash­ INTRODUCTION ington (table 1, fig. 1). It also contains two extensive valley-fill aquifers designated by the U.S. Environmen­ tal Protection Agency as the sole source of water for The U.S. Geological Survey (USGS) National Spokane, Washington; Missoula, Montana; and their Water-Quality Assessment (NAWQA) Program began surrounding suburban areas. at full scale in 1991 (Hirsch and others, 1988). Goals of The headwaters of the Clark Fork begin along the the NAWQA Program are to assess the quality of sur­ continental divide near Butte, Montana. At St. Regis, face and ground water and aquatic biological condi­ Montana, upstream from its confluence with the Flat- tions in the Nation’s major river basins and aquifer head River, the Clark Fork has an annual mean dis­ systems. Included in the assessments are attempts to charge of 7,225 ft3/s (Shields and others, 2001). The characterize both the natural and human factors affect­ three forks of the Flathead River drain much of Glacier ing environmental conditions, determine spatial patterns National Park and surrounding wilderness areas and of variability, and identify trends over time. NAWQA include Hungry Horse Reservoir, one of the largest Program studies employ consistent data-collection and hydroelectric reservoirs in the Columbia River system. analysis methods, thus allowing for aggregation of the The Flathead River flows into Flathead Lake, the larg­ information at the regional and national levels and for est freshwater lake in the Western United States, having comparisons over a wide range of geographic and envi­ a surface area of 192 mi2. Flowing out through a hydro- ronmental settings. electric dam that regulates the level of Flathead Lake, Typically, NAWQA Program studies consist of an the Flathead River joins the Clark Fork as its largest initial phase of planning and review of existing infor­ tributary with an annual mean discharge of 11,850 ft3/s mation. A sampling strategy is designed to build upon (Shields and others, 2001). More than 350 mi down- previous information and to address water-quality stream from its headwaters, the Clark Fork enters Pend issues of concern in the study area. An intensive data- Oreille Lake in Idaho (after passing through three rela­ collection, interpretation, and reporting phase follows tively small hydroelectric reservoirs at Thompson Falls for 3 to 4 years. Low-intensity data collection then is and Noxon, Montana, and Cabinet Gorge at the Mon­ conducted for 5 to 6 years at a few key sites to maintain tana-Idaho State boundary). With a depth of about data continuity over time and to monitor trends and 1,170 ft and containing about 13 mi3 of water, Pend identify emerging water-quality issues. NAWQA stud­ Oreille Lake is one of the deepest and largest lakes (in ies are intended to repeat monitoring cycles at approxi­ volume) in the Western United States. The Pend Oreille mately 10-year intervals. However, several NAWQA River flows out of Pend Oreille Lake through a hydro- studies will end after the first phase of intensive data electric dam, through northeastern Washington and two collection and reporting because of program funding more hydroelectric reservoirs, and joins the Columbia constraints. Among the studies to be discontinued is the River in British Columbia, Canada. At the international

2 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 Table 1. Surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area

[No., number; USGS, U.S. Geological Survey; mi2, square miles; ft, feet; MT, Montana; ID, Idaho; WA, Washington; Stream order, U.S. Geological Survey (1999)]

Drainage area (mi2 up- USGS stream Site gaging- from Elevation No. station gaging (ft above Stream (fig. 1) Site name No. Latitude Longitude station) sea level) order Clark Fork - Pend Oreille River Basin 1 C lark Fork at Turah Bridge near Bonner, MT ...... 12334550 46ο49'34" 113ο 48'48" 3,641 3,320 4 2 B itterroot River near Missoula, MT ...... 12352500 46ο 49'55" 114ο 03'11" 2,814 3,110 4 3 C lark Fork at St. Regis, MT ...... 12354500 47ο 18'07" 115ο 05'11" 10,709 2,600 5 4 Flathead River at Perma, MT ...... 12388700 47ο 22'03" 114ο 35'03" 8,795 2,469 5 5 L ightning Creek at Clark Fork, ID ...... 12392155 48ο 09'04" 116ο 10'56" 115 2,094 2 Spokane River Basin 6 St. Joe River at Red Ives Ranger Station, ID ...... 12413875 47ο 03'22" 115ο 21'08" 108 3,710 1 7 N orth Fork Coeur d’Alene River at Enaville, ID ...... 12413000 47ο 34'08" 116ο 15'06" 895 2,180 3 8 South Fork Coeur d’Alene River near Pinehurst, ID ...... 12413470 47ο 33'06" 116ο 14'13" 299 2,190 3 9 Spokane River near Post Falls, ID ...... 12419000 47ο 42'11" 116ο 58'37" 3,840 2,003 5 10 Spokane River at 7 Mile Bridge near Spokane, WA...... 12424500 47ο44' 25 " 117ο 31'10" 5,020 1,624 5

boundary, the Pend Oreille River drains an area of The study area has a complex geologic history about 25,200 mi2 (or about 79 percent of the study involving multiple episodes of uplift, igneous activity, area) and has an annual mean discharge of 26,760 ft3/s erosion, and sedimentation caused primarily by glacial (Kimbrough and others, 2001). and fluvial processes. The area consists mainly of coniferous forest-covered mountains and ridges inter­ The Spokane River Basin covers approximately spersed with river valleys. Elevations range from more 2 6,600 mi , or about 21 percent of the study area. The than 10,000 ft above sea level in the mountains of Spokane River begins at the outlet of Coeur d’Alene northwestern Montana and Glacier National Park to Lake in northern Idaho. Coeur d’Alene Lake covers less than 1,500 ft at the confluence of the Spokane and about 50 mi2; its two primary inflows are the Coeur Columbia Rivers. d’Alene and St. Joe Rivers, whose headwaters are in Both continental and maritime influences affect subranges of the Bitterroot Mountains west of the the climate of the study area. Most of the annual pre­ Idaho-Montana boundary. A hydroelectric dam on the cipitation falls between late autumn and spring, much Spokane River downstream from the lake outlet also of it as snow. Precipitation ranges from approximately regulates the Coeur d’Alene Lake level. After flowing 100 in. in the mountains of northwestern Montana and through three more hydroelectric dams, the Spokane northern Idaho to less than 15 in. in the drier intermon­ River near downtown Spokane, Washington, has an tane valleys in Montana and plateau areas near the con­ annual mean discharge of 6,765 ft3/s (Kimbrough and fluence of the Spokane and Columbia Rivers in eastern others, 2001). Downstream from the city is yet another Washington. Mountain snowmelt runoff from April small hydroelectric dam, and a large hydroelectric res­ through July dominates streamflow conditions. Typi­ ervoir (Lake Spokane, also known as Long Lake) cre­ cally, major floods are caused by weather systems from ated in the early 1900s. The Spokane River then enters the Pacific Ocean bringing warm wind and rain that Lake Roosevelt, the reservoir on the Columbia River rapidly melt snowpack accumulated at low to middle created by Grand Coulee Dam in eastern Washington. elevations.

Introduction 3 117° 49° CANADA UNITED STATES

Pend

IDAHO Priest Oreille Lake

WASHINGTON

KALISPELL Priest INDIAN RESERVATION Lightning ° Creek River 116 Sandpoint River 118° Pend 5 Priest Oreille River River Lake Clark Clark Fork ° ull 48 River B SPOKANE INDIAN MONTANANoxon Rock RESER­ Creek VATION IDAHO Lake North Spokane Spokane Little Fork 10 9 Post Falls Coeur d'Alene Fork Spokane River Spokane 7

Hangman Coeur Enaville d'Alene Kellogg Lake River Pinehurst Coeur d'Alene 8 South Creek Fork COEUR Bunker Hill D'ALENE Superfund Site St. INDIAN St Maries Joe RESER­ River VATION 6

47°

BRITISH Base from U.S. Geological Survey digital data. COLUMBIA Hydrologic unit maps, 1:100,000, 1994; rivers ALBERTA and streams, 1:250,000, 1994; Albers Equal- Northern Area Projection. Standard parallels 46° 00', River 48° 30', and 115° 00', 45° 00'. No false easting or false northing WASHINGTON Rocky MONTANA

Columbia Study Mtns area

OREGON IDAHO

Figure 1. Location of the Northern Rockies Intermontane Basins study area and surface-water-quality sampling sites in Montana, Idaho, and Washington.

4 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 114° EXPLANATION CANADA UNITED STATES Superfund site GLACIER Basin boundary

North Surface-water sampling site 4 and number (site names NATIONAL listed in table below) Fork

West Glacier Middle Clark Fork - Pend Oreille River Basin Columbia PARK Falls 1 Clark Fork at Turah Bridge near Bonner, Montana 2 Bitterroot River near Missoula, Montana Hungry Kalispell Horse 113° 3 Clark Fork at St. Regis, Montana ° Reservoir 115 Fork 4 Flathead River at Perma, Montana 5 Lightning Creek at Clark Fork, Idaho

South Flathead Spokane River Basin Lake 6 St. Joe River at Red Ives Ranger Station, Idaho 7 North Fork Coeur d'Alene River at Enaville, Idaho

FLATHEAD 8 South Fork Coeur d'Alene River near Pinehurst, Idaho er Riv Fork 9 Spokane River near Post Falls, Idaho 10 Spokane River at Seven Mile Bridge near Spokane, INDIAN Washington CONTINENT 3 4 Flathead St. Perma AL Regis Clark RESERVATION Superior

Fork Frenchtown Blackfoot River Missoula

Bonner N e 2 v a d 1 a Clark Creek

Rock DIVIDE Blackfoot r e

Little Riv Riv Clark Creek

Fork er Creek Superfund Fork Site

Hamilton Flint ve

Warm Springs Sil

Creek

Anaconda r

Bow Cr

° eek itterroot itterroot

46 B Butte

0 10 20 30 40 50 MILES

0 10 20 30 40 50 KILOMETERS

Introduction 5 Table 2. Land cover in the Northern Rockies Intermontane Basins the first miners to the upper Clark Fork Basin in Mon­ study area tana in the 1860s and to north Idaho’s Coeur d’Alene [mi2, square miles] mining district in the 1880s. By the early 1900s, the mines and smelters surrounding Butte, Montana, and Area Classification (mi2) Percent the South Fork Coeur d’Alene River valley were among the largest mining and industrial areas in the Forest ...... 23,534 74.8 Nation. In Montana, copper was the major product. Rangeland ...... 3,364 10.7 However (in order of the quantity extracted between Agricultural (including orchards) ...... 2,626 8.4 1880 and 1972), the area also produced zinc, manga­ Bare land (including rock, mountain peaks nese, lead, silver, cadmium, bismuth, selenium, tellu­ above tree line, glaciers, snowfields, tundra) 821 2.6 rium, and gold (Shavers and others, 1991). In Idaho, Water and wetlands ...... 762 2.4 silver was the primary product, as well as large amounts Urban ...... 356 1.1 of lead and zinc. In both areas, large-scale ore process­ Total ...... 31,463 100 ing and mining ended in the early 1980s; however, some mining continues on a much-reduced basis com­ pared with historical levels. Approximately 56 percent of the land in the study Mining and ore-processing activities generated area is publicly owned (primarily national and State large amounts of metal-enriched waste materials that forests, Glacier National Park, and designated wilder­ entered the Clark Fork and the South Fork Coeur ness areas). About 37 percent is privately owned and d’Alene River and their tributaries. An estimated about 7 percent is within the Coeur d’Alene, Flathead, 100 million tons of mining and ore-processing wastes Kalispell, and Spokane Indian Reservations (Maret and were produced and discharged to the headwaters of the Dutton, 1999). Almost 75 percent of the study area is Clark Fork and its tributaries during 1880 to 1982 covered by forest. Rangeland and agricultural land (Andrews, 1987). A similar amount was produced in make up about 11 and 8 percent, respectively (table 2). Idaho, more than half of which is estimated to have Only slightly more than 1 percent of the study area is entered the South Fork Coeur d’Alene River and its classified as urban (U.S. Geological Survey, 1996). tributaries (Long, 1998). The population of the NROK study area was about Elevated concentrations of trace elements (metals) 720,000 in the 2000 census: 250,000 in Montana, in streams and rivers, channel and flood-plain sedi­ 110,000 in Idaho, and 360,000 in Washington. Popula­ ments, and aquatic biota have been documented in the tion in the study area increased by more than 20 per- Clark Fork-Pend Oreille and Spokane River Basins cent between 1990 and 2000. Kootenai County in Idaho, downstream from historical mining and ore-processing containing the cities of Coeur d’Alene and Post Falls, areas (Johns and Moore, 1987; Moore and Luoma, grew by almost 56 percent. Ravalli County in Montana 1990; Lambing, 1991; Phillips and Lipton, 1995; (covering much of the Bitterroot River drainage) in- Horowitz and others, 1993, 1995a, 1995b; Beckwith, creased almost 45 percent in population in the 1990s. 1996; Beckwith and others, 1997; Hornberger and oth­ Population in Stevens and Pend Oreille Counties (adja­ ers, 1997; Woods and Beckwith, 1997; Maret and Dut­ cent to the Spokane, Washington, metropolitan and ton, 1999; Maret and Skinner, 2000; Grosbois and suburban areas) grew about 30 percent (U.S. Census others, 2001; Beckwith, 2002). As a result, several Bureau Website http://quickfacts.census.gov/qfd). Much of operable units along Silver Bow Creek and the Clark this low-density population growth occurred in subur­ Fork (including their flood plains) downstream from ban, undeveloped forest, agricultural, or rangeland Butte, Montana, to Milltown Reservoir (a small hydro- areas. electric reservoir at the confluence with the Blackfoot River) collectively make up the largest contiguous “Superfund” (U.S. Environmental Protection Agency Environmental History environmental remediation) site in the Nation. Metal- enriched sediments also appear to have been trans- About 1,600 active and abandoned hard-rock ported as far downstream as Priest River, Idaho, where mines are known to exist in the NROK study area Pend Oreille River bed sediments contain elevated con­ (Maret and Dutton, 1999). Placer gold deposits brought centrations of arsenic, cadmium, copper, lead, mercury,

6 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 and zinc, compared with background concentrations channels and drainage systems, and altered flood and (Beckwith, 2002). runoff patterns (Rabe and Flaherty, 1974). A 21-mi2 area of the lower South Fork Coeur Early municipal and industrial sewer systems dis­ d’Alene River valley is the Nation’s next-largest Super- charged directly to nearby rivers and streams with little fund site. Metal-enriched sediments have been trans- or no treatment. In the Butte-Anaconda, Montana, area, ported downstream and deposited in the bed, banks, settling ponds for controlling mine and smelter wastes and extensive flood plain and wetlands of the Coeur were constructed in the early 1900s, and more advanced d’Alene River, as well as on the bottom of Coeur treatment such as liming/precipitation was initiated in d’Alene Lake (Horowitz and others, 1993, 1995a, the 1950s (Phillips and Lipton, 1995). Other than low, 1995b; Woods and Beckwith, 1997). Elevated concen­ wooden dams constructed at various points across the trations of trace elements also have been reported in the South Fork Coeur d’Alene River valley, a system of bed and bank sediments of the Spokane River as far settling ponds was not constructed in this mining dis­ downstream as its confluence with the Columbia River trict until the late 1960s, and some of these received in Washington (Bortleson and others, 1994; Grosbois municipal wastewater as well (Cornell, Howland, and others, 2001; Beckwith, 2002). Hayes and Merryfield, Engineers and Planners, 1964). Although municipal and industrial dischargers Mining activities also have affected ground-water now employ advanced wastewater-treatment processes, quality, which has the potential to further affect surface- in late summer the wastewater discharges from Mis­ water quality. For example, when large-scale mining soula, Montana; Coeur d’Alene and Post Falls, Idaho; ended in the Butte, Montana, area in the early 1980s, and Spokane, Washington, contribute significant pro- pumping to remove water from the vast complex of portions of the streamflow and nutrient loads carried by underground mine shafts and the mile-wide, 1,300-ft- the Clark Fork and Spokane Rivers. Interstate nutrient- deep open-pit mine ceased. Surface runoff and ground management efforts have been underway in both the water continues filling these abandoned workings. Clark Fork and Spokane River Basins since the 1980s. Without intervention, highly acidic, metal-enriched Nevertheless, in late summer thick mats of attached, water could overtop the pit, enter adjacent alluvial filamentous, green algae grow in the Clark Fork (Land aquifers, and eventually reach the Clark Fork early in and Water Consulting, Inc., written commun., 1998), the 21st century (Moore and Luoma, 1990). In Idaho, and Lake Spokane has a history of nuisance algae ground water flowing under and through deposits of blooms, including toxic blue-green strains (Soltero and mine wastes and metal-enriched sediments is a con­ others, 1973, 1974; Raymond A. Soltero, Eastern tinuing source of dissolved lead and zinc to the South Washington University, oral and written communs., Fork Coeur d’Alene River and its tributaries (Barton, 1975–2001; Ken Merrill, Washington Department of 2002). Ecology, oral and written communs., 2001–2002). Extensive timber harvest also occurred throughout The effects of agriculture on water quality in the the forested mountains of the NROK study area. Early NROK study area are less pronounced than in many logging practices were highly disruptive and produced other NAWQA Program study areas. However, as in large-scale deforestation, erosion, sedimentation, and many other parts of the West, livestock grazing has destabilized streambanks and channels (Rabe and Fla­ altered riparian areas, stream channels, and flood plains. herty, 1974). For example, entire drainages were clear- Large tracts of forest land were cleared for large-scale cut and “splash dams” were built, which formed tem­ dryland agriculture in the extreme southwestern por­ porary lakes that were periodically and suddenly tion of the study area, beginning in the early 1900s. breached (often with explosives), thereby releasing a Soil-erosion rates from agricultural areas south and torrent of cut logs, logging debris, and sediment down- west of Coeur d’Alene Lake can be among the highest stream. Natural forest fires, combined with uncontrolled in the Nation (Rabe and Flaherty, 1974). burning of logging debris, disturbed additional large areas of forest. Also, large areas surrounding the smelt­ ers in Idaho and Montana were devegetated by acidic Water-Quality Sampling and Analysis precipitation and toxic fumes. Consequently, many watersheds in the NROK study area show the cumula­ Water-quality samples were collected at 10 NAWQA tive effects of deforestation, destabilization of stream sites throughout the Clark Fork-Pend Oreille and

Introduction 7 Spokane River Basins (fig. 1, table 1). These sites rep­ and alkalinity were determined in the field using stan­ resent major subbasins and stream reaches or specific dard instruments and methods as specified for the hydrologic and environmental areas of interest. For NAWQA Program (Shelton, 1994). Subsamples for example, the sites at the Clark Fork at Turah Bridge chemical analysis were split and processed in the field near Bonner, Montana (site 1), and the South Fork in mobile laboratories. Documented protocols used Coeur d’Alene River near Pinehurst, Idaho (site 8), are consistently by all NAWQA Program studies included located near the downstream boundaries of the Super- the use of a 10-port cone splitter constructed of Teflon fund sites and represent those areas in the respective (to produce representative subsamples of solid-phase river basins affected by large-scale, mining-associated constituents), specific procedures for positive-pressure contamination. Lightning Creek at Clark Fork, Idaho filtration (using capsule filters with a nominal pore size (site 5), represents a forested, mountainous basin of 0.45 micrometer), sample preservation (conducted where considerable logging and road-building activi­ in isolation chambers), and rigorous equipment clean­ ties have occurred. The sites on the Flathead River at ing to minimize contamination during sampling and Perma, Montana (site 4), and the Spokane River near sample processing (Shelton, 1994). Post Falls, Idaho (site 9), are downstream from large Major ion and nutrient concentrations were ana­ lakes. lyzed by the USGS National Water Quality Laboratory All but two NROK NAWQA sampling sites were according to methods described by Fishman and Fried- located at USGS gaging stations where streamflow data man (1989) and Fishman (1993). Trace elements were being collected. A new gaging station was estab­ (except for mercury) were analyzed by inductively lished in water year 1999 at the St. Joe River at Red coupled plasma-mass spectrometry as described by Ives Ranger Station, Idaho (site 6), to represent rela­ Faires (1993) and Jones and Garbarino (1999). Organic tively undisturbed reference conditions in the forested, carbon was analyzed according to the method of Bren­ mountainous watersheds of the Northern Rocky Moun­ ton and Arnett (1993). Total recoverable mercury was tains. Another NROK NAWQA sampling site was analyzed by cold vapor atomic absorption by methods established on the Spokane River at 7 Mile Bridge near described by Fishman and Friedman (1989). Spokane, Washington (site 10), downstream from the wastewater-treatment facility and storm-sewer outfalls of the city and surrounding metropolitan area. Stream- STREAMFLOW AND WATER-QUALITY DATA flow at this site was determined by adding the dis­ charge values from the wastewater-treatment facility Summaries and Graphical Displays of Data and from gaging stations on the Spokane River and near the mouth of Hangman Creek approximately 10 Boxplots are used throughout this report as a con­ mi upstream; little additional inflow occurs in this venient means of graphically portraying the distribu­ reach where the river is confined in a bedrock canyon. tion of the data. In a boxplot, the middle line within the Water-quality samples were collected approxi­ box represents the median, or 50th percentile, value. mately 9 to 12 times per year at each site from late When arranged in ascending order, one-half of the val­ 1998 to mid-2001 (water years 1999 – 2001). Samples ues are greater than the median and one-half are less were collected more frequently during periods of than the median. The top of the box represents the 75th increasing and high streamflow (spring snowmelt run- percentile (75 percent of the values are less than this off) and less frequently during receding or base-flow value). The bottom of the box represents the 25th per­ conditions. Considerable effort was made to collect centile (25 percent of the values are less than this approximately similar numbers of samples in each value). The difference between the 25th and 75th per­ increment (deciles) of streamflow (figs. 2–11, back of centile values (and comprising half of the values) is the report). interquartile range. In the boxplots presented in this Water samples for analysis of chemical constitu­ report, the lines (called whiskers) extending from the ents and suspended sediment were collected using top of the box represent values that are as much as 1.5 standard USGS depth-integrating samplers and using times the interquartile range greater than the 75th per­ isokinetic and cross-section integrating sampling meth­ centile value. Conversely, the whiskers extending from ods (Edwards and Glysson, 1988; Ward and Harr, the bottom of the box represent values as much as 1.5 1990). Specific conductance, pH, water temperature, times the interquartile range less than the 25th percen-

8 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 EXPLANATION the mean daily values for the respective periods of for boxplots shown in record (figs. 2–5 and 8–11). At three sites—Lightning figures 12 through 40 Creek at Clark Fork, Idaho; St. Joe River at Red Ives Ranger Station, Idaho; and Spokane River at 7 Mile 27 Number of measurements or samples Bridge near Spokane, Washington—the hydrologic Far outlier data period of streamflow record was insufficient to compute long-term statistics. Therefore, only sampling Outlier dates are plotted on the study-period hydrograph for 75th percentile plus 1.5 times the IQR these sites for water years 1999 – 2001 in figures 6, 7, 75th percentile and 11. In water year 2000, streamflow at sites in the Spokane River Basin was near or slightly greater than ) the long-term mean, but at Clark Fork sites, streamflow IQR ( Median (50th percentile) was less than the long-term mean. Streamflow in water quartile range year 2001 was considerably less than the long-term 25th percentile Inter mean at all sites, ranging from about 75 percent of the mean at the Clark Fork at Turah Bridge near Bonner, 25th percentile minus Montana, to about 40 percent at the North Fork Coeur 1.5 times the IQR d’Alene River at Enaville, Idaho. Outlier Far outlier NUTRIENTS Concentrations of dissolved ammonia, nitrite plus nitrate, ammonia plus total organic nitrogen, orthophos­ tile value. Values that lie outside the ranges indicated phorus, total phosphorus, suspended organic carbon, by the whiskers are shown as solid dots (outliers) and and dissolved organic carbon are summarized in table as circles (far outliers). These extreme values do not 4. Also included for comparison in table 4 are median imply a problem with the quality of the data, but indi- values from 85 relatively undisturbed watersheds across cate the rareness of such values within the overall data the Nation from NAWQA and other national program set. studies (Clark and others, 2000). Nutrient data from the NROK NAWQA study include many censored or esti­ mated values, not only because of the small concentra- Physical and Chemical Characteristics tions present in rivers and streams in the NROK NAWQA study area, but also because of changes in Common physical and chemical characteristics of analytical methodology and data reporting conventions rivers and streams at the 10 surface-water sampling at the USGS National Water Quality Laboratory that sites in the NROK NAWQA study area are statistically occurred during the study. Therefore, for the graphical summarized in table 3 and depicted in boxplots in fig- depiction (boxplots) of nutrient data provided in figures ures 12 –19 (back of report). In general, rivers and 20 and 21, censored data were assigned a value of one- streams in the study area contain small concentrations half the reported “less than” value, and estimated val­ of dissolved substances and exhibit small values for ues were used directly. specific conductance, hardness, alkalinity, and dis- The median total nitrogen concentration at most solved solids. Dissolved oxygen concentrations gen- NROK sites was smaller than the median concentra­ erally were near saturation at all sites during the study tions reported by Clark and others (2000) at 85 rela­ and, therefore, were not included in the tables or fig- tively undisturbed sites from around the Nation. How­ ures. ever, the median total nitrogen concentration at the South Fork Coeur d’Alene River near Pinehurst, Idaho, was 106 percent of the national median, and the STREAMFLOW median concentration at the Spokane River at 7 Mile In water year 1999, streamflow at NROK sam- Bridge near Spokane, Washington, was more than dou­ pling sites was greater than or near (96 – 131 percent) ble the national median. Both of these sites are down-

Streamflow and Water-Quality Data 9 8 27 88 27 26 73 24 57 19 89 94 13 25 21 257 214 107 160 131 106 (mg/L) solids, Dissolved calculated , Montana; ID, µ m) 23 48 95 80 27 29 92 72 23 30 94 81 20 45 98 81 18 50 80 69 sediment Suspended than 62 (percent less 3 9 1 6 1 6 1 3 1 6 1 µ m, micrometers; MT 26 27 23 20 13 18 131 168 280 (mg/L) sediment Suspended , ) 3 4 ockies Intermontane Basins study area, water 27 46 27 14 86 48 24 41 97 21 83 96 87 18 13 10 148 128 120 field CaCO (mg/L as Alkalinity , calcium carbonate, 3 ) 3 4 27 64 27 15 77 51 24 97 21 81 94 89 18 15 10 192 160 106 124 CaCO (mg/L as Hardness 0 7.0 2.0 9.5 0 6.8 0 8.0 3.0 6.0 ater ( ° C) 27 19.0 27 21.5 24 22.0 21 23.0 18 25.0 W temperature 7.5 8.5 8.1 7.1 8.6 7.8 7.5 8.5 8.1 7.8 8.4 8.2 6.6 7.5 7.1 27 27 24 21 18 units) pH, field (standard grees Celsius; mg/L, milligrams per liter; CaCO 27 27 39 20 95 20 18 12 36 26 153 413 352 177 117 277 224 158 193 173 ( µ S/cm) Specific conductance ° C; C, de 6 27 27 24 21 18 /s) 287 929 482 162 3 5,280 1,415 1,660 4,160 4,090 2,120 (ft 13,700 35,300 32,400 10,100 Streamflow , MT µ S/cm, microsiemens per centimeter at 25 ork, ID Site name . . . . . gis, MT ...... urah Bridge near Bonner T er near Missoula, MT . . . . . er at Perma, MT v v ork at ork at St. Re /s, cubic feet per second; No. of samples Minimum Maximum Median No. of samples Minimum Maximum Median No. of samples Minimum Maximum Median No. of samples Minimum Maximum Median No. of samples Minimum Maximum Median 3 ashington] lark F itterroot Ri lark F C B C Flathead Ri Lightning Creek at Clark F A , W Selected physical and chemical characteristics for samples collected at surface-water-quality sampling sites in the Northern R 1 2 3 4 5 (fig. 1) Site No. able 3. Idaho; W T [No., number; ft years 1999–2001

10 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 Table 3. Selected physical and chemical characteristics for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001— Continued

Alkalinity, Suspended Dissolved Specific pH, field Water Hardness field Suspended sediment solids, Site No. Streamflow conductance (standard temperature (mg/L as (mg/L as sediment (percent less calculated 3 (fig. 1) Site name (ft /s) (µS/cm) units) (°C) CaCO3) CaCO3) (mg/L) than 62 µm) (mg/L)

6 St. Joe River at Red Ives Ranger Station, ID No. of samples ...... 17 17 17 17 17 17 17 17 8 Minimum ...... 46 26 6.7 0 12 12 1 40 22 Maximum...... 2,190 51 8.0 15.0 24 25 9 92 34 Median ...... 181 41 7.5 6.0 18 19 1 70 0

7 North Fork Coeur d’Alene River at Enaville, ID No. of samples ...... 28 28 28 28 28 28 28 28 15 Minimum ...... 144 25 6.7 1.5 10 10 1 60 21 Maximum...... 18,200 62 7.7 15.5 23 41 207 93 34 Median ...... 1,465 41 7.3 5.8 19 18 1 79 31

8 South Fork Coeur d’Alene River near Pinehurst, ID No. of samples ...... 33 33 33 33 33 33 32 30 33 Minimum ...... 82 46 6.6 1.5 18 12 1 55 31 Maximum...... 4,890 328 7.5 18.0 136 38 302 88 203 Median ...... 413 147 7.2 7.5 56 25 3 75 87

9 Spokane River near Post Falls, ID No. of samples ...... 29 29 29 29 29 28 29 29 29 Minimum ...... 242 41 7.0 2.0 16 16 1 50 29 Maximum...... 28,000 71 7.7 25.0 23 21 3 89 39 Median ...... 4,510 50 7.4 8.5 20 18 1 75 35

10 Spokane River at 7 Mile Bridge near Spokane, WA No. of samples ...... 27 26 27 27 27 27 27 26 27 Minimum ...... 680 57 6.9 3.5 23 21 1 4 38 Maximum...... 26,800 303 8.1 16.0 133 115 116 96 170 Median ...... 5,940 95 7.6 8.5 39 35 3 79 59 Streamflow andWater-Quality Data 11 .5 .7 .55 0 0 9 0 0 0 0 4 0 0 1.4 2.9 1.8 1.3 2.6 1.6 1.3 4.6 2.35 0 0 1.1 5.1 3.3 11 12 10 Carbon, organic, dissolved (mg/L as C) .3 .2 .2 .2 .2 .5 9 5 1 3.4 0 0 2.8 4 4 0 0 4.5 <.2 <.2 <.2 <.2 >.2 <.2 55.6 10 10 11 11 Carbon, 100 organic, (mg/L as C) suspended otal .038 .0045 .004 .183 .0185 .004 .117 .02 .004 .0035 .011 .172 .029 T e.002 e.002 3 1 3.7 0 0 21 13 61.9 24 12.5 27 18 16 88.9 27 (mg/L as P) phosphorus Intermontane Basins study area, water alue; <, less than; >, greater —, no data nd other national monitoring programs .007 .001 .01 .002 .008 .002 .003 .001 .023 .007 8 9 7 Ortho­ <.001 <.001 <.001 <.001 <.001 21 13 61.9 24 33.3 27 33.3 18 13 72.2 27 25.9 dissolved (mg/L as P) phosphorus, cent; e, estimated v organic-N nitrate-N + .2385 .189 .137 + e.171 0.247 added to (mg/L as N) otal nitrogen, T nitrite ammonia ashington; %, per W A , W .30 .115 .19 .66 .20 .62 .17 .23 .86 total e.07 e.06 e.07 e.06 e.05 e.08 7 2 8.3 3 2 7.4 21 33.3 18 16 88.9 24 27 11.1 27 nitrogen, Ammonia (mg/L as N) plus organic .064 .022 .025 .247 .101 .159 .0385 .102 .019 .20 .017 plus Nitrite 2 9.5 0 0 4 5 2 7.4 , Montana; ID, Idaho; <.005 <.005 <.005 <.005 nitrate, 21 18 24 16.7 27 18.5 27 dissolved (mg/L as N) .045 .002 .024 .002 .018 .0045 .017 .004 .011 .003 9 8 5 8 9 <.002 <.002 <.002 <.002 <.002 21 42.9 18 44.4 24 20.8 27 29.6 27 33.3 dissolved Ammonia, (mg/L as N) , phosphorus; C, carbon; MT ...... alues alues alues alues alues ork, ID alues alues alues alues alues . . . . . gis, MT Site name . . . . . urah Bridge near . . . . . T er near Missoula, MT . . . . . er at Perma, MT v v , MT ork at St. Re ork at No. of samples No. of censored or e v No. of samples No. of censored or e v % censored or e v % censored or e v Minimum Maximum Median Minimum Maximum Median No. of samples No. of censored or e v % censored or e v Minimum Maximum Median No. of samples No. of censored or e v % censored or e v Minimum Maximum Median No. of samples No. of censored or e v % censored or e v Minimum Maximum Median Bonner lark F itterroot Ri ightning Creek at Clark F B C L Flathead Ri C lark F 2001, and comparative median concentrations in samples collected for the National Water-Quality Assessment Program a – Nutrient and organic carbon concentrations in samples collected at surface-water-quality sampling sites the Northern Rockies 4 5 3 2 1 No. Site (fig. 1) ailable] able 4. av T [No., number; mg/L, milligrams per liter; N, nitrogen; P years 1999

12 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 Table 4. Nutrient and organic carbon concentrations in samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001, and comparative median concentrations in samples collected for the National Water-Quality Assessment Program and other national monitoring programs — Continued

Nitrite Ammonia Total nitrogen, plus plus organic nitrite + nitrate-N Ortho­ Carbon, Carbon, Site Ammonia, nitrate, nitrogen, added to phosphorus, Total organic, organic, No. dissolved dissolved total ammonia + organic-N dissolved phosphorus suspended dissolved (fig. 1) Site name (mg/L as N) (mg/L as N) (mg/L as N) (mg/L as N) (mg/L as P) (mg/L as P) (mg/L as C) (mg/L as C) 6 St. Joe River at Red Ives Ranger Station, ID 6 No. of samples ...... 17 17 17 17 17 7 0 No. of censored or e values...... 13 4 13 7 9 4 0 % censored or e values ...... 76.5 23.5 76.5 41.2 52.9 57.1 0 Minimum ...... <.002 <.005 e.05 <.001 e.003 <.2 .6 Maximum ...... 011 .053 .16 .004 .012 .2 1.7 Median ...... <.002 .009 .075 0.084 .0015 .005 <.2 .7 7 North Fork Coeur d’Alene River at Enaville, ID No. of samples ...... 28 28 28 28 28 11 11 No. of censored or e values...... 12 5 21 11 13 8 0 % censored or e values ...... 42.9 17.9 75 39.3 46.4 72.7 0 Minimum ...... <.002 <.005 e.06 <.001 e.003 <.2 0 Maximum ...... 014 .048 .36 .008 .189 1.5 1.3 Median ...... 002 .013 e.08 e.21 .003 .006 <.2 .74 8 South Fork Coeur d’Alene River near Pinehurst, ID No. of samples ...... 33 33 33 32 33 13 14 No. of censored or e values...... 0 0 7 1 0 5 0 % censored or e values ...... 0 0 21.9 3.1 0 38.5 0 Minimum ...... 006 .025 e.06 .002 .012 <.2 .4 Maximum ...... 408 .448 .62 .027 .171 1.5 .9 Median ...... 07 .128 .21 .338 .009 .032 .2 .6 9 Spokane River near Post Falls, ID

Streamflow andWater-Quality Data No. of samples ...... 27 27 27 27 27 10 11 No. of censored or e values...... 6 1 5 10 3 1 0 % censored or e values ...... 22.2 3.7 18.5 37 11.1 10 0 Minimum ...... <.002 <.005 e.05 <.001 e.005 .2 1.3 Maximum ...... 052 .257 .65 .133 .057 .5 3.7 Median ...... 004 .054 .13 .184 .0015 .011 .2 1.4 10 Spokane River at 7 Mile Bridge near Spokane, WA No. of samples ...... 27 27 27 27 27 11 11 No. of censored or e values...... 8 0 5 4 0 1 0 % censored or e values ...... 29.6 0 18.5 14.8 0 9.1 0 Minimum ...... <.002 .101 e.06 <.001 .006 <.2 1.1 Maximum ...... 067 2.86 .31 .108 .118 .4 2 Median ...... 004 .591 .15 .741 .012 .027 .2 1.6 13 National median for 85 undisturbed sites (Clark and others, 2000) ...... 020 .080 — .32 .010 .037 — — stream from wastewater-treatment facilities. Under of limited variation in the values or because of analyti­ conditions of low streamflow, treated wastewater from cal reporting limits that were too large to observe varia­ the city of Spokane composed as much as 9 to 11 per- tion over much of the range of ambient concentrations. cent of the discharge in the Spokane River at 7 Mile Dissolved arsenic concentrations were largest at Bridge in the late summer and early autumn in water the Clark Fork at Turah Bridge and at St. Regis, Mon­ years 1999 – 2001 (fig. 11). tana, and the Spokane River at 7 Mile Bridge near Spo­ The median total phosphorus concentration at all kane, Washington (table 5, fig. 22). These sites are NROK sites was smaller (often by a considerable downstream from the historical Butte-Anaconda min­ amount) than the median concentration at 85 undis­ ing and ore-processing areas in Montana and the city of turbed sites reported by Clark and others (2000). How- Spokane, Washington, metropolitan area. A similar pat- ever, the maximum concentration of total phosphorus tern was apparent for total recoverable arsenic (fig. 23). measured at six NROK NAWQA sites exceeded the In addition, several total recoverable arsenic concentra­ 0.1 mg/L threshold recommended for limiting nuisance tions (measured during high streamflow) at the South aquatic algae and plant growth in rivers or streams Fork Coeur d’Alene River near Pinehurst, Idaho, (down- (U.S. Environmental Protection Agency, 1986). These stream from the historical Coeur d’Alene mining and sites were the Clark Fork at Turah Bridge, Bitterroot ore-processing district) exceeded the maximum con­ River near Missoula, and Clark Fork at St. Regis, in centration at the Clark Fork at Turah Bridge (table 5). Montana; the North Fork Coeur d’Alene River at Median dissolved and total recoverable cadmium Enaville and the South Fork Coeur d’Alene River near concentrations were substantially larger at the South Pinehurst, in Idaho; and the Spokane River at 7 Mile Fork Coeur d’Alene River near Pinehurst, Idaho, com­ Bridge near Spokane, in Washington. pared with other sites. Concentrations were moderately elevated, relative to concentrations at the remaining sites, at the Spokane River near Post Falls, Idaho, and ORGANIC CARBON at 7 Mile Bridge near Spokane, Washington (table 5, Dissolved and suspended organic carbon were figs. 24 and 25). sampled and analyzed at most NROK sites from late Dissolved copper concentrations were largest at 1998 to early 2000 (table 4). Analyses for carbon were the Clark Fork at Turah Bridge near Bonner and at St. discontinued in 2000, primarily because of the small Regis, Montana (table 5, fig. 26). Total recoverable concentrations routinely measured at NROK NAWQA copper concentrations also were largest at the Clark sites and also because of methodological changes at the Fork at Turah Bridge (fig. 27). USGS National Water Quality Laboratory. Dissolved lead concentrations were largest at the South Fork Coeur d’Alene River near Pinehurst, Idaho TRACE ELEMENTS (fig. 28), and generally were less than 1 µg/L at the remaining sites. Total recoverable lead concentrations Concentrations of selected trace elements of envi­ also were largest at the South Fork Coeur d’Alene ronmental concern in the NROK study area are sum­ River near Pinehurst and were one or more orders of marized in table 5. Methodological changes, varying magnitude larger than at the main-stem Clark Fork and analytical detection and data reporting (censoring) lim­ Spokane River sites (fig. 29), which also are down- its during the NROK NAWQA study made data analy­ stream from historical mining areas (fig. 1). sis, interpretation, and reporting difficult. These varying At the minimum and median hardness levels mea­ reporting limits affected statistical treatment of cen­ sured throughout the NROK NAWQA study, dissolved sored values, resulting in intervals rather than discrete lead concentrations in all 32 samples collected at the values for some medians (table 5). For the graphical South Fork Coeur d’Alene River near Pinehurst, Idaho, depictions (boxplots) of selected trace-element data in exceeded the Idaho criterion for chronic toxicity desig­ figures 22 – 32 (back of report), censored data were nated for the protection of aquatic life; 75 percent of assigned values of one-half the reported “less than” the dissolved lead concentrations exceeded the crite­ value, and estimated values were used directly. Never­ rion at the maximum hardness level measured. The theless, some of the boxplots appear distorted. For hardness-dependent chronic criterion is the 4-day aver- example, at sites having a large proportion of censored age concentration not to be exceeded more than once values, the boxplots appear compressed, either because every 3 years on average (Idaho Department of Envi-

14 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 Table 5. Selected trace-element data for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999 –2001

[No., number; µg/L, micrograms per liter; MT, Montana; ID, Idaho; WA, Washington; e, estimated value; %, percent; <, less than]

Cadmium, Cadmium, Copper, Lead, Lead, Mercury, Zinc, Zinc, Site Arsenic, Arsenic, total dissolved total dissolved Copper, total dissolved total total dissolved total No. dissolved recoverable (µg/L as recoverable (µg/L as recoverable (µg/L as recoverable recoverable (µg/L as recoverable (fig. 1) Site name (µg/L as As) (µg/L as As) Cd) (µg/L as Cd) Cu) (µg/L as Cu) Pb) (µg/L as Pb) (µg/L as Hg) Zn) (µg/L as Zn)

1 Clark Fork at Turah Bridge near Bonner, MT No. of samples ...... 24 23 24 23 24 23 24 23 16 24 22 No. of censored or e values . . . 0 0 22 17 0 14 21 9 15 0 14 % of censored or e values . . . . 0 0 91.7 73.9 0 60.9 87.5 39.1 93.8 0 63.6 Minimum ...... 3.1 3 e.02 .04 1.9 3.5 e.04 e.50 <.10 2.2 8 Maximum ...... 7.9 11 .04 <1.0 6.5 48.4 .10 10 <.30 8.1 90 Median ...... 5.5 6 <1.0 <.11 2.65 17.4 <1.0 1.2 <.30 3.9 <31

2 Bitterroot River near Missoula, MT No. of samples ...... 19 18 19 18 19 18 19 18 13 19 18 No. of censored or e values . . . 13 18 19 17 14 15 19 18 13 15 15 % of censored or e values . . . . 68.4 100 100 94.4 73.7 83.3 100 100 100 78.9 83.3 Minimum ...... 24 <1.0 e.02 <.04 .52 e.52 <.08 <1.0 <.10 <1.0 <1.0 Maximum ...... <2.0 <2.6 <1.0 1.9 .86 <20 <1.0 e1.0 <.30 <1.0 <40 Median ...... <1.0 <1.9 <1.0 <.11 <1.0 <12 <1.0 <1.0 <.30 <2.5 <31

3 Clark Fork at St. Regis, MT No. of samples ...... 22 22 22 22 22 22 22 22 16 22 22 No. of censored or e values . . . 5 14 22 22 5 15 21 19 16 7 16 % of censored or e values . . . . 22.7 63.6 100 100 22.7 68.2 95 86.4 100 31.8 72.7 Minimum ...... e.67 <1.0 e.02 e.02 <1.0 1.0 e.04 e.62 <.10 <1.0 1.5 Maximum ...... 2.4 3.1 <1.0 <1.0 2.4 21 .10 6.7 <.30 1.3 <40 Median ...... e1.6 2.2 <1.0 <.11 1.2 <12 – e12 <1.0 <1.0 <.30 <3.9 <31

4 Flathead River at Perma, MT No. of samples ...... 14 14 14 14 14 14 14 14 8 14 14 No. of censored or e values . . . 8 13 14 13 8 12 14 14 8 13 11 % of censored or e values . . . . 57.1 92.9 100 92.9 57.1 85.7 100 100 100 92.9 78.6 Minimum ...... 37 <1.0 e.02 <.04 .4 e.41 e.04 <1.0 <.10 <1.0 <1.0 Streamflow andWater-Quality Data Maximum ...... <2.0 <2.6 <1.0 <1.0 <1.0 <20.0 <1.0 <1.0 <.30 <3.0 <40 Median ...... 56 – <.9 <1.9 <1.0 .11 <1.0 <12 <1.0 <1.0 <.10 – <.30 <1.0 e17 –<31

5 Lightning Creek at Clark Fork, ID No. of samples ...... 17 17 17 17 17 17 17 17 10 17 17 No. of censored or e values . . . 17 17 16 17 13 17 11 17 10 13 16 % of censored or e values . . . . 100 100 94.1 100 76.5 100 64.7 100 100 76.5 94.1 Minimum ...... e.11 <1.9 e.02 <.04 e.16 e.41 e.05 e.51 <.30 <1.0 <1 Maximum ...... <2.0 <2.6 <1.0 <.11 <1.0 <20.0 <1.0 <1.0 <.30 <1.0 <31 Median ...... <.90 <2.6 <1.0 <.11 <1.0 <20.0 <1.0 <1.0 <.30 <3.6 <31 15 – 4 2 8 0 0 2.1 total 24 16.7 26 96 63 46 31 22 13 59.1 84 15 15 Zinc, <1.0 e20 e26 114 363 927 100 g/L as Zn) <31 <40 <31 µ µ µ µ 2,190 ( recoverable 0 0 8.5 0 0 0 0 3 1.8 4.5 24 76 39.5 26 22 90 53.5 32 16 15 93.8 21 14.3 66 Zn) <1.0 <3.5 <1.0 g/L as Zinc, 227 913 µ µ µ µ ( 2,120 dissolved , .66 <.10 <.30 <.30 <.10 <.30 <.30 <.10 <.30 <.10 <.30 <.30 <.10 <.30 <.30 total 18 18 17 17 23 19 83 12 12 15 15 g/L as Hg) 100 100 100 100 Mercury µ µ µ µ ( recoverable Basins study area, water years 1999 e.59 e.88 8 1.5 7.8 1.15 0 0 total Lead, 26 31 24 10 41.7 16 31 13 20 15 15 22 17 77.3 24 <1.0 <1.0 <1.0 <1.0 <1.0 g/L as Pb) 790 100 µ µ µ µ ( recoverable 25 19 e.04 e.06 e.04 1.6 1.4 0 0 2.1 4.4 <.10 <.08 Pb) g/L as 26 17 65 32 12 76 16 15 93.8 21 20 95.2 <1.0 <1.0 <1.0 <1.0 <1.0 Lead, µ µ µ µ ( dissolved , total .67 e.58 e.31 e.30 1.2 1.3 g/L as Cu) 26 18 69 31 21 68 14 24 17 70.8 16 16 22 22 µ µ µ µ 100 100 <20 <12 <20 <20 <12 <20 ( recoverable Copper <12 – <20 e11 – <12 , .5 .84 .54 e.16 e.18 1.5 Cu) g/L as 26 16 62 25 18 72 32 18 56 17 14 82.4 21 17 81 <3.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 µ µ µ µ Copper <10 ( dissolved .10 .23 .185 e.08 e.02 7 6 0 0 2.6 6.4 <.04 <.11 <.11 total 24 29.2 26 23 22 21 95 30 19 16 16 <1.0 <1.0 <1.0 <1.0 100 g/L as Cd) Cadmium, µ µ µ µ ( recoverable .05 .08 e.02 e.02 0 0 1.5 6.55 <.10 Cd) g/L as 25 18 72 26 17 65 17 17 32 18 21 21 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 µ µ µ µ 100 100 ( dissolved Cadmium, 2.7 3.0 24 23 95.8 26 25 96 15 15 31 22 71 13 22 20 91 <1.0 <1.0 <2.6 <1.0 <2.6 <1.9 <1.0 <2.6 <1.0 <1.9 g/L as As) 100 µ µ µ µ ( recoverable Arsenic, total 1.9 – e2.0 <1.9 – <2.6 .30 e.51 e.11 e.09 3.2 <.90 <.90 25 13 52 26 17 65 16 15 93.8 32 22 69 21 20 95 <1.0 <1.0 <2.0 <2.0 <2.0 <1.0 <2.0 <1.0 g/L as As) Arsenic, dissolved µ µ µ µ ( . . . . . er er at . . . . . v v alues alues alues alues alues alls, ID alues alues alues alues alues es Ranger . . . . . A W ...... Site name er at 7 Mile Bridge er near Post F . . . . . v v er at Red Iv v ork Coeur d’Alene Ri ork Coeur d’Alene Ri ville, ID No. of samples No. of censored or e v % of censored or e v Minimum Maximum Median No. of samples No. of censored or e v % of censored or e v Minimum Maximum Median No. of samples No. of censored or e v % of censored or e v Minimum Maximum Median No. of samples No. of censored or e v % of censored or e v Minimum Maximum Median No. of samples No. of censored or e v % of censored or e v Minimum Maximum Median near Spokane, Station, ID near Pinehurst, ID Ena orth F Spokane Ri Spokane Ri St. Joe Ri South F N Continued — 9 6 8 7 10 No. Site (fig. 1) able 5. Selected trace-element data for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane 2001 T

16 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 ronmental Quality, 1999; U.S. Environmental Protec­ comparison with results from the NROK NAWQA tion Agency, 2000). study. These studies covered the following geographic Although most total recoverable mercury concen­ areas: Upper Colorado River Basin (UCOL); Sacra­ trations were reported either as less than 0.10 or less mento River Basin (SACR); Great Salt Lake Basins than 0.30 µg/L (table 5), mercury was measured at (GRSL); and Nevada Basins and Range (NVBR). Cen­ detectable or estimated concentrations on one occasion sored values were set to one-half the reporting value, at the Clark Fork at Turah Bridge and on four occasions and “estimated” values were used directly. Along with at the South Fork Coeur d’Alene River near Pinehurst the NROK data, the distributions of these data are (fig. 30). The concentration reported for the Clark Fork graphically depicted (boxplots) in figures 33 – 40 (back at Turah Bridge was 0.12 µg/L from a sample collected of report). during high streamflow. At the South Fork Coeur Overall, median concentrations of dissolved d’Alene River near Pinehurst, three concentrations arsenic, dissolved and total recoverable copper, total ranging from 0.30 to 0.66 µg/L were measured in sam­ recoverable lead, and total recoverable zinc in the ples collected during high streamflow, and a concentra­ NROK study area appeared to be similar to or slightly tion of 0.15 µg/L was measured in a sample collected smaller than those reported for other Western NAWQA during low streamflow. study areas affected by historical mining activities Dissolved zinc concentrations were substantially (figs. 33, 35, 36, 38, and 40). Although the NROK elevated at the South Fork Coeur d’Alene and Spokane median total recoverable lead concentration was the River sites (table 5, fig. 31). These sites are downstream smallest among the three Western study areas com­ from historical mining areas (fig. 1); sites on the pared (fig. 38), concentrations in several samples from Spokane River are also downstream from Coeur the NROK study area were an order of magnitude d’Alene Lake. The elevated concentrations of zinc larger than the maximum concentrations in samples in the Spokane River indicate that a portion of the up- from the UCOL or GRSL study areas. Dissolved cad­ stream zinc input passes through Coeur d’Alene Lake. mium, dissolved lead, and total recoverable zinc at A similar pattern also was evident for total recoverable NROK sites were more variable than in the other study zinc concentrations (fig. 32). At the South Fork Coeur areas; concentrations ranged over nearly three orders of d’Alene River near Pinehurst, Idaho, dissolved zinc magnitude between the minimum and maximum val­ concentrations in all 32 samples exceeded both the ues. The largest range in concentration was measured chronic and acute criteria for the protection of aquatic for dissolved zinc, which exceeded three orders of life at all hardness levels measured throughout the magnitude in the NROK study area. study (Idaho Department of Environmental Quality, 1999; U.S. Environmental Protection Agency, 2000). The acute criterion is the 1-hour average concentration REFERENCES CITED not to be exceeded more than once every 3 years on average. At the Spokane River near Post Falls, Idaho, Andrews, E.D., 1987, Longitudinal dispersion of trace 22 of 26 (85 percent) dissolved zinc concentrations metals in the Clark Fork River, Montana, in Averett, exceeded both the chronic and acute criteria. At the R.C., and McKnight, D.M., eds., Chemical quality Spokane River at 7 Mile Bridge near Spokane, Wash­ of water and the hydrologic cycle: Chelsea, Mich., ington, at the median hardness level, 9 of 24 (38 per- Lewis Publishers, p. 179–191. cent) dissolved zinc concentrations exceeded the chronic Barton, G.J., 2002, Dissolved cadmium, zinc, and lead criterion, and 5 of 24 concentrations (21 percent) ex­ loads from ground-water seepage into the South ceeded the acute criterion. Fork Coeur d’Alene River system, northern Idaho, 1999: U.S. Geological Survey Water-Resources Investigations Report 01–4274, 130 p. COMPARISON WITH OTHER NATIONAL WATER- Beckwith, M.A., 1996, Water-quality data collected dur­ QUALITY ASSESSMENT PROGRAM STUDIES ing floods in the Coeur d’Alene River, northern Idaho, February 1996: U.S. Geological Survey Fact Trace-element data from sites in other NAWQA Sheet FS–219–96, 4 p. Program study areas in the Western United States that ––––– 2002, Selected trace-element and synthetic- have a history of mining activities were obtained for organic compound data for streambed sediment

References Cited 17 from the Clark Fork-Pend Oreille and Spokane Grosbois, C.A., Horowitz, A.J., Smith, J.J., and Elrick, River Basins, Montana, Idaho, and Washington, K.A., 2001, The effect of mining and related activi­ 1998: U.S. Geological Survey Open-File Report ties on the sediment-trace element geochemistry of 02–336, 26 p. Lake Coeur d’Alene, Idaho, USA, Part III—down­ Beckwith, M.A., Woods, P.F., and Berenbrock, Charles, stream effects—the Spokane River Basin: Hydro- 1997, Trace-element concentrations and transport logical Processes, v. 15, p. 855–875. in the Coeur d’Alene River, Idaho, water years Hirsch, R.M., Alley, W.M., and Wilber, W.G., 1988, 1993–94: U.S. Geological Survey Open-File Concepts for a National Water-Quality Assessment Report 97–398, 7 p. Program: U.S. Geological Survey Circular 1021, Bortleson, G.C., Cox, S.E., Munn, M.D., Schumaker, 42 p. R.J., Block, E.K., Bucy, L.K., and Cornelius, S.B., Hornberger, M.I., Lambing, J.H., Luoma, S.N., and Axt­ 1994, Sediment-quality assessment of Franklin D. mann, E.V., 1997, Spatial and temporal trends of Roosevelt Lake and the upstream reach of the trace metals in surface water, bed sediment, and Columbia River, Washington, 1992: U.S. Geologi­ biota of the upper Clark Fork Basin, Montana, cal Survey Open-File Report 94–315, 130 p., 1985–95: U.S. Geological Survey Open-File 1 map. Report 97–669, 84 p., 1 app. Brenton, R.W., and Arnett, T.L., 1993, Methods of anal­ Horowitz, A.J., Elrick, K.A., Robbins, J.A., and ysis by the U.S. Geological Survey National Water Cook, R.B., 1993, Effect of mining and related Quality Laboratory—determination of dissolved activities on the sediment-trace element geochemis­ organic carbon by UV-promoted persulfate oxida­ try of Lake Coeur d’Alene, Idaho, USA, Part 1— tion and infrared spectrometry: U.S. Geological surface sediments: Hydrological Processes, v. 7, Survey Open-File Report 92–480, 12 p. p. 403–423. Clark, G.M., Mueller, D.K., and Mast, M.A., 2000, ––––– 1995a, Effect of mining and related activities Nutrient concentrations and yields in undeveloped on the sediment-trace element geochemistry of stream basins of the United States: Journal of the Lake Coeur d’Alene, Idaho, USA, Part II— American Water Resources Association, v. 36, sub-surface sediments: Hydrological Processes, no. 4, p. 849–860. v. 9, p. 35–54. ––––– 1995b, A summary of the effects of mining and Cornell, Howland, Hayes and Merryfield, Engineers and related activities on the sediment-trace metal Planners, 1964, Mine, industrial, and domestic geochemistry of Lake Coeur d’Alene, Idaho, waste disposal study for the South Fork Coeur USA: Journal of Geochemical Exploration, v. 52, d’Alene River: Record no. B2763, 102 p., 5 apps. p. 135–144. Edwards, T.K., and Glysson, D.G., 1988, Field methods Idaho Department of Environmental Quality, 1999, for measurement of fluvial sediment: U.S. Geologi­ Water quality standards and wastewater treatment cal Survey Open-File Report 86–531, 118 p. requirements, title 1, chapter 2: Boise, Idaho Faires, L.M., 1993, Methods of analysis by the U.S. Geo­ Department of Environmental Quality, IDAPA logical Survey National Water Quality Laboratory — 58.01.02.210.07, accessed September 20, 2002, determination of metals in water by inductively at URL http://www.state.id.us/adm/adminrules/rules/ coupled plasma-mass spectrometry: U.S. Geologi­ idapa58/58index.htm cal Survey Open-File Report 92–634, 28 p. Johns, C., and Moore, J., 1987, Trace metals in reservoir Fishman, M.J., 1993, Methods of analysis by the U.S. sediments of the lower Clark Fork River, Montana: Geological Survey National Water Quality Lab­ Bozeman, Mont., Montana Water Resources Cen­ oratory—determination of inorganic and organic ter, 52 p. constituents in water and fluvial sediments: U.S. Jones, S.R., and Garbarino, J.R., 1999, Methods of anal­ Geological Survey Open-File Report 93–125, ysis by the U.S. Geological Survey National Water 217 p. Quality Laboratory—determination of arsenic and Fishman, M.J., and Friedman, L.C., 1989, Methods for selenium in water and sediment by graphite furnace determination of inorganic substances in water and atomic absorption spectrometry: U.S. Geological fluvial sediments: U.S. Geological Survey Tech­ Survey Open-File Report 98–639, 39 p. niques of Water-Resources Investigations, Book 5, Kimbrough, R.A., Smith, R.R., Ruppert, G.P., Wiggins, Chap. A1, 545 p. W.D., Knowles, S.M., and Renslow, V.F., 2001,

18 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 Water resources data, Washington, water year 2000: tana, water year 2000: U.S. Geological Survey U.S. Geological Survey Water-Data Report Water-Data Report MT–00–1, 639 p. WA –00–1, 541 p. Smith, J.D., Lambing, J.H., Nimick, D.A., Parrett, C., Lambing, J.H., 1991, Water-quality and transport char­ Ramey, M., and Schafer, W., 1998, Geomorphol­ acteristics of suspended sediment and trace ele­ ogy, flood-plain tailings, and metal transport in ments in streamflow of the upper Clark Fork Basin the upper Clark Fork Valley, Montana: U.S. Geo­ from Galen to Missoula, Montana, 1985–90: U.S. logical Survey Water-Resources Investigations Geological Survey Water-Resources Investigations Report 98–4170, 56 p. Report 91–4139, 73 p. Soltero, R.A., Gasperino, A.G., and Graham, W.G., Long, K.R., 1998, Production and disposal of mill tail­ 1973, An investigation of the cause and effect of ings in the Coeur d’Alene mining region, Shoshone eutrophication in Long Lake, Washington: Cheney, County, Idaho; preliminary estimates: U.S. Geolog­ Wash., Eastern Washington State College, Comple­ ical Survey Open-File Report 98–0595, 14 p. tion Report, O.W.R.R. Project 143–34–10E– 3996–5501, 86 p. Maret, T.R., and Dutton, D.M., 1999, Summary of infor­ ––––– 1974, Further investigation of the cause and effect mation on synthetic organic compounds and trace of eutrophication in Long Lake, Washington: elements in tissue of aquatic biota, Clark Fork-Pend Cheney, Wash., Eastern Washington State College, Oreille and Spokane River Basins, Montana, Idaho, Completion Report, Washington Department of and Washington, 1974–96: U.S. Geological Survey Ecology, Project 74–025A, 85 p. Water-Resources Investigations Report 98–4254, U.S. Environmental Protection Agency, 1986, Quality 61 p. criteria for water—1986: U.S. Environmental Pro­ Maret, T.R., and Skinner, K.D., 2000, Concentrations of tection Agency, EPA 440/5–86–001 (variously selected trace elements in fish tissue and streambed paged). sediment in the Clark Fork-Pend Oreille and Spo­ ––––– 2000, Water quality standards, federally promul­ kane River Basins, Washington, Idaho, and Mon­ gated water quality standards, 40 CFR 131.36, tana, 1998: U.S. Geological Survey Water- accessed on Nov. 20, 2002, at URL Resources Investigations Report 00–4159, 26 p. http://www.epa.gov/ost/standards/wqslibrary/nv/131.36.pdf Moore, J.N., and Luoma, S.N., 1990, Hazardous wastes U.S. Geological Survey, 1996, 1990 residential land use from large-scale metal extraction—a case study: derived from 1970s land use and population data: Environmental Science and Technology, v. 24, U.S. Geological Survey, scale 1:250,000. p. 1278–1285. ––––– 1999, Enhanced river reach file 1.2: U.S. Geolog­ Phillips, G., and Lipton, J., 1995, Injury to aquatic ical Survey Open-File Report 99–457, scale resources caused by metals in Montana’s Clark 1:500,000. Fork River Basin—historic perspective and over- Ward, J.R., and Harr, C.A., 1990, Methods for collection view: Canadian Journal of Fisheries and Aquatic and processing of surface-water and bed-material Sciences, v. 52, p. 1990–1993. samples for physical and chemical analyses: U.S. Geological Survey Open-File Report 90–140, 71 p. Rabe, F.W., and Flaherty, D.C., 1974, The river of green Woods, P.F., and Beckwith, M.A., 1997, Nutrient and and gold: Moscow, University of Idaho Research trace-element enrichment of Coeur d’Alene Lake, Foundation, 98 p. Idaho: U.S. Geological Survey Water-Supply Paper Shavers, B., Fiege, M., Martin, D., and Quivik, F., 1991, 2485, 93 p. Butte and Anaconda revisited—an overview of early-day mining and smelting in Montana: Butte, Mont., Montana Bureau of Mines and Geology, Special Publication 99, 64 p. Shelton, L.R., 1994, Field guide for collecting and pro­ cessing stream-water samples for the National Water-Quality Assessment Program: U.S. Geologi­ cal Survey Open-File Report 94–455, 42 p. Figures 2 -40 Shields, R.R., White, M.K., Ladd, P.B., Chambers, C.L., and Dodge, K.A., 2001, Water resources data, Mon­

References Cited 19 Back to body of report

FIGURES 2–40

EXPLANATION for boxplots shown in figures 12 through 40

27 Number of measurements or samples Far outlier Outlier 75th percentile plus 1.5 times the IQR 75th percentile ) IQR

( Median (50th percentile) quartile range

25th percentile Inter

25th percentile minus 1.5 times the IQR Outlier Far outlier Percent of time Number of occasions samples were collected at Clark Fork at Turah streamflow is Streamflow, in Bridge near Bonner, Montana (12334550), water years 1999–2001 equaled or cubic feet 7 exceeded per second Decile Number of 6 90 Less than 500 1 samples, 27 80 500 to 621 2 5 70 622 to 705 3

SAMPLES 4 60 706 to 787 4 50 788 to 869 5 3 40 870 to 978 6 2 30 979 to 1,122 7 20 1,123 to 1,479 8 1

10 1,480 to 2,321 9 NUMBER OF 0 Less than 10 Greater than 2,321 10 1 2 3 4 5 6 7 8 9 10 DECILE

Water Mean daily streamflow, in Percent of mean daily streamflow year cubic feet per second for the period of record

1985–2001 (period of record) 1,218 1999 1,374 114 2000 764 63 2001 908 75 7,000

Daily streamflow Mean daily streamflow— 6,000 Water years 1985–2001 Water-quality sample collected

5,000 PER SECOND

4,000

3,000 , IN CUBIC FEET

2,000 STREAMFLOW 1,000

0 . . . Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. WATER YEAR 1999 WATER YEAR 2000 WATER YEAR 2001

Figure 2. Selected streamflow statistics and water-quality sampling dates for the Clark Fork at Turah Bridge near Bonner, Montana (12334550). (Site 1 in figure 1)

Figures 2–40 23 Percent of time Number of occasions samples were collected at Bitterroot River streamflow is Streamflow, in near Missoula, Montana (12352500), water years 1999–2001 equaled or cubic feet 6 exceeded per second Decile Number of 5 90 Less than 637 1 samples, 27 80 637 to 758 2 4 70 759 to 871 3 SAMPLES 60 872 to 995 4 3 50 996 to 1,137 5 40 1,138 to 1,357 6 2 30 1,358 to 1,830 7 20 1,831 to 3,288 8 1

10 3,289 to 6,281 9 NUMBER OF 0 Less than 10 Greater than 6,281 10 1 2 3 4 5 6 7 8 9 10 DECILE

Water Mean daily streamflow, in Percent of mean daily streamflow year cubic feet per second for the period of record

1898–2001 (period of record) 2,460 1999 2,484 96 2000 1,689 65 2001 1,440 56 16,000

Daily streamflow Mean daily streamflow— 14,000 Water years 1898–2001 Water-quality sample collected

12,000

PER SECOND 10,000

8,000 , IN CUBIC FEET 6,000

4,000 STREAMFLOW

2,000

0 . . . Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. WATER YEAR 1999 WATER YEAR 2000 WATER YEAR 2001

Figure 3. Selected streamflow statistics and water-quality sampling dates for the Bitterroot River near Missoula, Montana (12352500). (Site 2 in figure 1)

24 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 Percent of time Number of occasions samples were collected at Clark Fork at St. streamflow is Streamflow, in Regis, Montana (12354500), water years 1999–2001 equaled or cubic feet 5 exceeded per second Decile Number of 90 Less than 2,237 1 4 samples, 24 80 2,237 to 2,655 2 70 2,656 to 2,993 3 3 SAMPLES 60 2,994 to 3,340 4 50 3,341 to 3,784 5 2 40 3,785 to 4,482 6 30 4,483 to 5,971 7 1 20 5,972 to 10,156 8

10 10,157 to 18,544 9 NUMBER OF 0 Less than 10 Greater than 18,544 10 1 2 3 4 5 6 7 8 9 10 DECILE

Water Mean daily streamflow, in Percent of mean daily streamflow year cubic feet per second for the period of record

1930–2001 (period of record) 7,183 1999 7,674 106 2000 5,229 72 2001 4,223 58 40,000

Daily streamflow Mean daily streamflow— 35,000 Water years 1930–2001 Water-quality sample collected

30,000

PER SECOND 25,000

20,000 , IN CUBIC FEET 15,000

10,000 STREAMFLOW

5,000

0 . . . Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. WATER YEAR 1999 WATER YEAR 2000 WATER YEAR 2001

Figure 4. Selected streamflow statistics and water-quality sampling dates for the Clark Fork at St. Regis, Montana (12354500). (Site 3 in figure 1)

Figures 2–40 25 Percent of time Number of occasions samples were collected at Flathead River streamflow is Streamflow, in at Perma, Montana (12388700), water years 1999–2001 equaled or cubic feet 5 exceeded per second Decile Number of 90 Less than 5,736 1 4 samples, 21 80 5,736 to 6,986 2 70 6,987 to 8,282 3 3 SAMPLES 60 8,283 to 9,404 4 50 9,405 to 10,549 5 2 40 10,550 to 11,578 6 30 11,579 to 12,576 7 1 20 12,577 to 13,797 8

10 13,798 to 17,216 9 NUMBER OF 0 Less than 10 Greater than 17,216 10 1 2 3 4 5 6 7 8 9 10 DECILE

Water Mean daily streamflow, in Percent of mean daily streamflow year cubic feet per second for the period of record

1984–2001 (period of record) 11,580 1999 11,120 96 2000 11,545 99 2001 7,040 61 40,000

Daily streamflow Mean daily streamflow— 35,000 Water years 1984–2001 Water-quality sample collected

30,000

PER SECOND 25,000

20,000 , IN CUBIC FEET 15,000

10,000 STREAMFLOW

5,000

0 . . . Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. WATER YEAR 1999 WATER YEAR 2000 WATER YEAR 2001

Figure 5. Selected streamflow statistics and water-quality sampling dates for the Flathead River at Perma, Montana (12388700). (Site 4 in figure 1)

26 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 4,000 Number of samples, 18 Daily streamflow Water-quality sample 3,500 collected

3,000

PER SECOND 2,500

2,000 , IN CUBIC FEET 1,500

1,000 STREAMFLOW

500

0 . . . Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. WATER YEAR 1999 WATER YEAR 2000 WATER YEAR 2001

Figure 6. Daily streamflow and water-quality sampling dates for Lightning Creek at Clark Fork, Idaho (12392155). (Site 5 in figure 1)

Figures 2–40 27 3,000 Number of samples, 17 Daily streamflow Water-quality sample collected 2,500

2,000 PER SECOND

1,500 , IN CUBIC FEET

1,000

STREAMFLOW 500

0 . ug. . . Oct. Dec. Feb. Apr June A Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. WATER YEAR 1999 WATER YEAR 2000 WATER YEAR 2001

Figure 7. Daily streamflow and water-quality sampling dates for the St. Joe River at Red Ives Ranger Station, Idaho (12413875). (Site 6 in figure 1)

28 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 Percent of time Number of occasions samples were collected at the North Fork Coeur streamflow is Streamflow, in d'Alene River at Enaville, Idaho (12413000), water years 1999–2001 equaled or cubic feet 7 exceeded per second Decile Number of 6 90 Less than 250 1 samples, 28 80 250 to 314 2 5 70 315 to 410 3

SAMPLES 4 60 411 to 562 4 50 563 to 843 5 3 40 844 to 1,266 6 2 30 1,267 to 1,912 7 20 1,913 to 2,988 8 1

10 2,989 to 5,033 9 NUMBER OF 0 Less than 10 Greater than 5,033 10 1 2 3 4 5 6 7 8 9 10 DECILE

Water Mean daily streamflow, in Percent of mean daily streamflow year cubic feet per second for the period of record

1911–2001 (period of record) 1,892 1999 2,243 119 2000 2,029 107 2001 763 40 22,500

Daily streamflow 20,000 Mean daily streamflow— Water years 1911–2001 Water-quality sample collected 17,500

15,000 PER SECOND

12,500

10,000 , IN CUBIC FEET

7,500

5,000 STREAMFLOW 2,500

0 . . . Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. WATER YEAR 1999 WATER YEAR 2000 WATER YEAR 2001

Figure 8. Selected streamflow statistics and water-quality sampling dates for the North Fork Coeur d’Alene River at Enaville, Idaho (12413000). (Site 7 in figure 1)

Figures 2–40 29 Percent of time Number of occasions samples were collected at the South Fork Coeur streamflow is Streamflow, in d'Alene River near Pinehurst, Idaho (12413470), water years 1999–2001 equaled or cubic feet 9 exceeded per second Decile 8 Number of samples, 33 90 Less than 97 1 7 80 97 to 118 2 6 70 119 to 147 3 SAMPLES 5 60 148 to 192 4 50 193 to 272 5 4 40 273 to 392 6 3 30 393 to 573 7 2 20 574 to 821 8 1 10 822 to 1,298 9 NUMBER OF 0 Less than 10 Greater than 1,298 10 1 2 3 4 5 6 7 8 9 10 DECILE

Water Mean daily streamflow, in Percent of mean daily streamflow year cubic feet per second for the period of record

1987–2001 (period of record) 526 1999 687 131 2000 584 111 2001 232 44 5,000

Daily streamflow 4,500 Mean daily streamflow— Water years 1987–2001 Water-quality sample 4,000 collected

3,500 PER SECOND 3,000

2,500

, IN CUBIC FEET 2,000

1,500

1,000 STREAMFLOW

500

0 . . . Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. WATER YEAR 1999 WATER YEAR 2000 WATER YEAR 2001

Figure 9. Selected streamflow statistics and water-quality sampling dates for the South Fork Coeur d’Alene River near Pinehurst, Idaho (12413470). (Site 8 in figure 1)

30 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 Percent of time Number of occasions samples were collected at the Spokane River streamflow is Streamflow, in near Post Falls, Idaho (12419000), water years 1999–2001 equaled or cubic feet 7 exceeded per second Decile Number of 6 90 Less than 911 1 samples, 30 80 911 to 1,266 2 5 70 1,267 to 1,612 3

SAMPLES 4 60 1,613 to 2,084 4 50 2,085 to 2,988 5 3 40 2,989 to 4,526 6 2 30 4,527 to 6,884 7 20 6,885 to 11,215 8 1

10 11,216 to 17,206 9 NUMBER OF 0 Less than 10 Greater than 17,206 10 1 2 3 4 5 6 7 8 9 10 DECILE

Water Mean daily streamflow, in Percent of mean daily streamflow year cubic feet per second for the period of record

1913–2001 (period of record) 6,206 1999 7,534 121 2000 6,853 110 2001 2,691 43 30,000

Daily streamflow Mean daily streamflow— Water years 1913–2001 25,000 Water-quality sample collected

20,000 PER SECOND

15,000 , IN CUBIC FEET

10,000

STREAMFLOW 5,000

0 . . . Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. Oct. Dec. Feb. Apr June Aug. WATER YEAR 1999 WATER YEAR 2000 WATER YEAR 2001

Figure 10. Selected streamflow statistics and water-quality sampling dates for the Spokane River near Post Falls, Idaho (12419000). (Site 9 in figure 1)

Figures 2–40 31

30,000 15 Number of samples, 28 Daily streamflow Percent of streamflow from Spokane Wastewater- 25,000 Treatment Facility Water-quality sample collected

20,000 10

15,000

10,000 5 ASTEWATER-TREATMENT FACILITY ASTEWATER-TREATMENT W STREAMFLOW, IN CUBIC FEET PER SECOND IN CUBIC FEET STREAMFLOW, 5,000 FROM SPOKANE STREAMFLOW OF PERCENT

0 0 ug. Oct. Dec. Feb. Apr. June A Oct. Dec. Feb. Apr. June Aug. Oct. Dec. Feb. Apr. June Aug. WATER YEAR 1999 WATER YEAR 2000 WATER YEAR 2001

FigureFigure 11. 11. Daily Daily streamflow streamflow and andwate water-qualityr-quality sampling sampling dates fordates the fridgeSpokane near River Spokane, at Seven Mile Bridge near Spokane, WashingtonWashington (12424500). (12424500). (Site (Site 10 in 10 figure in figure 1) 1)

32 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 100,000 60,000 24 21 29 27 30,000 28 27

10,000 27 33 6,000 3,000 18 17 PER SECOND

1,000 600 300

100

, IN CUBIC FEET 60 30

10 6 3 STREAMFLOW

1 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 12. Distribution of streamflow values for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1)

500

27

400

33 26 ANCE, IN 300 20

20 200 27 SPECIFIC CONDUCT 100 29

MICROSIEMENS PER CENTIMETER 28 17 18

0 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 13. Distribution of specific conductance values for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1)

Figures 2–40 33 9.0

27 27 24 8.5 21

26 17 8.0 28 29 18 33 7.5 ARD UNITS pH, IN AND

ST 7.0

6.5

6.0 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 14. Distribution of onsite pH values for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1)

30

18 29 25 21 27 24 27 20 33

TURE, IN 26 17 28 15

10 DEGREES CELSIUS TER TEMPERA WA

5

0 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 15. Distribution of water temperature values for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1)

34 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 200

150

, 33 ) 27 3 24 AS CaCO ( 100 21 27 HARDNESS 50 27 IN MILLIGRAMS PER LITER

17 28 29 18

0 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 16. Distribution of hardness values for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1)

150

24 125 27 , ) 3 21 100 27 AS CaCO ( 75

50 28 33 ALKALINITY 27 IN MILLIGRAMS PER LITER 17 25 28 18

0 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 17. Distribution of alkalinity values for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1)

Figures 2–40 35 500 23 32 300 28 27 26 27

100 ,

60

30

20 17 10 18 6 SUSPENDED SEDIMENT

IN MILLIGRAMS PER LITER 29 3

1 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 18. Distribution of suspended sediment concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1)

300

27

250

33 200 27 24

150 VED SOLIDS, 27 19

100 DISSOL IN MILLIGRAMS PER LITER

50 8 15 29 8

0 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 19. Distribution of dissolved solids concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1)

36 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 5 27 3

27 33 1 27 24 28 27 0.60 21 18 0.30 17

0.10

0.06

NITROGEN, IN MILLIGRAMS PER LITER 0.03 L TA TO 0.01 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 20. Distribution of total nitrogen concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

0.3 27 0.1 27 0.06 21

0.03

0.01 27 17 27 0.006 18

0.003 24

32 0.001

0.0006 28 PHOSPHORUS, IN MILLIGRAMS PER LITER 0.0003 L TA

TO 0.0001 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 21. Distribution of total phosphorus concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

Figures 2–40 37 9 24 8

7

6

5

VED ARSENIC, 4 25

3

DISSOL 22

IN MICROGRAMS PER LITER 2 19 14 17 16 21 32 26 1

0 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 22. Distribution of dissolved arsenic concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

14 31

12 23

10 ARSENIC,

8

6 RECOVERABLE L 4 22 22

TA 24 IN MICROGRAMS PER LITER

TO 26 2 18 14 17 15

0 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 23. Distribution of total recoverable arsenic concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

38 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 30

10

6

3

1 32 24 19 22 14 17 17 21 26 25 0.6

VED CADMIUM, 0.3

DISSOL 0.1

IN MICROGRAMS PER LITER 0.06

0.03

0.01 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 24. Distribution of dissolved cadmium concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

30

10

6

3 18

CADMIUM, 30

1 23 22 14 16 22 26 24 0.6

0.3

RECOVERABLE 0.1 L 17 IN MICROGRAMS PER LITER TA 0.06 TO 0.03

0.01 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 25. Distribution of total recoverable cadmium concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

Figures 2–40 39 10 24 6

3 22 32 26

COPPER, 25 19 1 14

VED 17 0.6 17 21 DISSOL

0.3 IN MICROGRAMS PER LITER

0.1 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 26. Distribution of dissolved copper concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

60

30 22 31 26 18 14 17 16 22 24 10

COPPER, 6

3 23

1 RECOVERABLE

L 0.6 TA IN MICROGRAMS PER LITER

TO 0.3

0.1 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 27. Distribution of total recoverable copper concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

40 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 30 32

10

6

3 26 25

1 24 19 22 14 17 16 21 0.6 VED LEAD, 0.3 DISSOL 0.1

IN MICROGRAMS PER LITER 0.06

0.03

0.01 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 28. Distribution of dissolved lead concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

1,000

600

300

100

60 22 30 24 23 10 22 26 31

RECOVERABLE LEAD, 6 L

TA 3 IN MICROGRAMS PER LITER TO 18 1 17 14 15 0.6

0.3 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 29. Distribution of total recoverable lead concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

Figures 2–40 41 0.7

0.6 , Y 23 0.5

0.4

0.3 RECOVERABLE MECUR

L 0.2 16 13 16 8 10 12 15 17 18 TA IN MICROGRAMS PER LITER TO 0.1

0 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 30. Distribution of total recoverable mercury concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

42 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 3,000 32

1,000 600

300

100 26 21 24 60

30 VED ZINC,

10 24

DISSOL 6 22 17 3 IN MICROGRAMS PER LITER 19 14 16

1 0.6

0.3 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 31. Distribution of dissolved zinc concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

3,000

1,000 600

300 31 24 22 22 26 100 60 22 30 18 14 15 17

10 RECOVERABLE ZINC,

L 6 TA 3 IN MICROGRAMS PER LITER TO

1 0.6

0.3 1 2 3 4 5 6 7 8 9 10 SAMPLING SITE

Figure 32. Distribution of total recoverable zinc concentrations for samples collected at surface-water-quality sampling sites in the Northern Rockies Intermontane Basins study area, water years 1999–2001. (Site locations shown in figure 1 and described in table 1; censored values were set to one-half the reporting value, and “estimated” values were used directly)

Figures 2–40 43 600 181 300 106

100

60

122 39 30 185 VED ARSENIC, 10

6 DISSOL

IN MICROGRAMS PER LITER 3

1

0.6 NROK UCOL SACR GRSL NVBR STUDY AREA Figure 33. Distribution of dissolved arsenic concentrations for samples collected in surface water in National Water-Quality Assessment study areas in the Western United States affected by historical mining activities. (NROK, Northern Rockies Intermontane Basins; UCOL, Upper Colorado River; SACR, Sacramento River; GRSL, Great Salt Lake Basins; NVBR, Nevada Basin and Range; censored values were set to one-half the reporting value, and “estimated” values were used directly)

30 63 101 12 10 6 19

3

1

0.6

0.3

0.1

0.06

VED CADMIUM, IN MICROGRAMS PER LITER 0.03

DISSOL 0.01 NROK UCOL GRSL NVBR STUDY AREA

Figure 34. Distribution of dissolved cadmium concentrations for samples collected in surface water in National Water-Quality Assessment study areas in the Western United States affected by historical mining activities. (NROK, Northern Rockies Intermontane Basins; UCOL, Upper Colorado River; SACR, Sacramento River; GRSL, Great Salt Lake Basins; NVBR, Nevada Basin and Range; censored values were set to one-half the reporting value, and “estimated” values were used directly)

44 Surface-Water-Quality, Clark Fork-Pend Oreille and Spokane River Basins, 1999–2001 1,000 600

300

100 208 60 105 30 167 251 10 106 6

3

1 0.6 VED COPPER, IN MICROGRAMS PER LITER 0.3

DISSOL 0.1 NROK UCOL SACR GRSL NVBR STUDY AREA

Figure 35. Distribution of dissolved copper concentrations for samples collected in surface water in National Water-Quality Assessment study areas in the Western United States affected by historical mining activities. (NROK, Northern Rockies Intermontane Basins; UCOL, Upper Colorado River; SACR, Sacramento River; GRSL, Great Salt Lake Basins; NVBR, Nevada Basin and Range; censored values were set to one-half the reporting value, and “estimated” values were used directly)

600 40 300

100 79 60

30

10 6

3 RECOVERABLE COPPER, L 1 TA IN MICROGRAMS PER LITER 0.6 TO

0.3

0.1 NROK UCOL STUDY AREA

Figure 36. Distribution of total recoverable copper concentrations for samples collected in surface water in National Water-Quality Assessment study areas in the Western United States affected by historical mining activities. (NROK, Northern Rockies Intermontane Basins; UCOL, Upper Colorado River; censored values were set to one-half the reporting value, and “estimated” values were used directly)

Figures 2 – 40 45 46 and Range;censoredvaluesweresettoone-halfthereportingvalue,“estimated”useddirectly) Intermontane Basins;UCOL,UpperColoradoRiver;SACR,SacramentoGRSL,GreatSaltLakeNVBR,NevadaBasin Assessment studyareasintheW Figure 37. Surface-Water-Quality, ClarkFork-PendOreilleand SpokaneRiverBasins,1999–2001 DISSOLVED LEAD, IN MICROGRAMS PER LITER Figure 38. censored valuesweresettoone-half thereportingvalue,and“estimated”valueswereuseddirectly) Rockies IntermontaneBasins;UCOL, UpperColoradoRiver;SACR,SacramentoGRSL,GreatSalt LakeBasins; Quality Assessmentstudyareasin theW 0.03 0.06 100 0.6 0.1 0.3 10 30 60 6 1 3 DistributionofdissolvedleadconcentrationsforsamplescollectedinsurfacewaterNationalW Distribution oftotalrecoverablelead concentrationsforsamplescollectedinsurfacewaterNational W NROK estern UnitedStatesaffectedbyhistoricalminingactivities.(NROK,NorthernRockies TOTAL RECOVERABLE LEAD, IN 80

MICROGRAMS PER LITER 1,000 600 300 100 0.6 0.1 0.3 60 10 30 3 1 6 estern UnitedStatesaffectedbyhistorical miningactivities.(NROK,Northern NROK 138 UCOL 71 STUDY STUDY UCOL 28 AREA AREA GRSL 28 GRSL 7 NVBR 6 ater -Quality ater - values weresettoone-halfthereportingvalue,and“estimated”useddirectly) UCOL, UpperColoradoRiver;SACR,SacramentoGRSL,GreatSaltLakeBasins;NVBR,NevadaBasinandRange;censored study areasintheW Figure 39. DISSOLVED ZINC, IN MICROGRAMS PER LITER 10,000 6,000 1,000 3,000 censored valuesweresettoone-half thereportingvalue,and“estimated”valueswereuseddirectly) Rockies IntermontaneBasins;UCOL, UpperColoradoRiver;SACR,SacramentoGRSL,GreatSalt LakeBasins; Quality Assessmentstudyareasin theW Figure 40. 600 300 100 0.3 0.6 10 30 60 6 1 3 Distribution ofdissolvedzincconcentrationsforsamplescollectedinsurfacewaterNationalW Distributionoftotalrecoverablezinc concentrationsforsamplescollectedinsurfacewaterNational W estern UnitedStatesaffectedbyhistoricalminingactivities.(NROK,NorthernRockiesIntermontaneBasins; NROK 211

TOTAL RECOVERABLE ZINC, IN MICROGRAMS PER LITER 10,000 1,000 3,000 6,000 600 300 100 0.6 30 10 60 1 3 6 estern UnitedStatesaffectedbyhistorical miningactivities.(NROK,Northern UCOL 243 NROK 172 STUDY STUDY SACR 162 UCOL 44 AREA AREA GRSL 6 GRSL 187 ater NVBR 90 -Quality Assessment Figures 2 ater - – 40 47 Michael A. Beckwith / Surface-Water-Quality Data Collected for the Northern Rockies Intermontane Basins NAWQA Program in the Clark Fork-Pend Oreille and Spokane River Basins, Montana, Idaho, and Washington, Water Years 1999–2001 / OFR 02 – 472 Printed on recycled paper